Exactly! He's still afraid of strangers, but now he just sits quietly behind us instead of growling at them. He very rarely growls at us now -- maybe a couple of times a year when he's very worked up. Then we drag him up to his room, and he's very quickly repentant. :)
I'm glad yours is better. I wanted to follow up because the poster said fear may be a part of this dog's misbehavior, in addition to the territorial or possession issues.
Sometimes I get lazy and don't say everything that should be said. I also hate to over-advise because I am not sure we really know the situation this owner is faced with...
...But I think you would agree, when a dog is fear-aggressive or even fearful and fractious, peeing all over themselves, it is no help to be harsh or punish, but the last thing you want to do is reward it with any kind of "ooh honey it's Oooookaaaay" kind of soothing or petting. Don't beat them for it, but certainly don't REWARD it... simply take them abruptly away (it has to feel like a direct consequence) from you and everyone else every time until keeping themselves together is the only way they get to stay in the group.